Recently, the European photovoltaic technology and innovation platform (ETIPPV) and the European photovoltaic industry association (SolarPowerEurope) jointly issued the "solar skin: the chance of green city", Outlines the photovoltaic (BIPV) building integration technology (that is, the "solar skin") in the power of Europe, decarburization, accelerate the city clean energy transformation and create new employment opportunities can make contribution, and put forward the policy Suggestions on advancing BIPV application. Key points of the report are as follows:

First, BIPV will play a key role in the decarbonisation of Energy in Europe

Globally, cities consume more than two-thirds of the world's energy and emit a similar proportion of carbon dioxide. Buildings account for 36% of global terminal energy consumption and nearly 40% of total direct and indirect CARBON dioxide emissions. The construction sector currently accounts for 49 per cent of the EU's energy needs and 36 per cent of its greenhouse gas emissions. The EU's construction industry needs to reduce its carbon emissions by about 90 per cent by 2050 to meet the Paris climate agreement. Eu cities therefore need to accelerate the deployment of renewable energy and increase investment in energy efficiency, especially in buildings.

At present, renewable energy provides only 24 per cent of the energy for urban buildings in the EU, and its development is subject to specific geographical, aesthetic and physical constraints related to urban planning, architectural requirements and the preservation of cultural heritage. Although rooftop solar installations are increasingly competitive in the market, roofs represent only a small fraction of the usable surface area of buildings, so much of the potential for renewable energy on the building's exterior walls has yet to be tapped. BIPV technology makes full use of the outer walls of buildings to generate electricity directly for heating, cooling and electric cars. It reduces the need for large-scale expansion and improves the stability of urban grids, which are becoming "electrified". The combination of local photovoltaic power generation, energy storage and supply and demand management makes the building a smaller unit in the smart grid, and connecting multiple smart buildings will contribute to the widespread deployment of smart grid technology. The BIPV module can be combined with insulation and other components to increase the energy efficiency of the building. Its modular character is applicable to almost any urban environment: roofs, facades, Windows, noise barriers, roads, etc. Its flexible design enables the city to maintain the architectural character and preserve the cultural heritage.

At present, BIPV has achieved a high level of technical maturity, and the flexibility of its design is well demonstrated by the numerous buildings throughout the European Union. Europe is a global leader in BIPV technology. Developing BIPV can promote and foster supporting industries, change Europe's urban energy landscape, improve the living conditions of urban residents and create jobs. This emerging industry is a key prerequisite for reducing the city's carbon footprint. In addition, PV module manufacturing can expand the European industry to a huge global market. Driven by the near-zero Energy Building (NZEB) policy and the future capacity Building (PEB), the development of new BIPV materials and concepts, as well as the design and innovation of energy-efficient building materials combined with BIPV, has become an important part of the development strategy of the PV and building sectors. This requires a multidisciplinary research and development programme, including photovoltaic manufacturing, building materials and certification bodies. Breakthroughs in technology, applications and business models are needed to transform today's BIPV niche into the mass market of the future.

Ii. BIPV is an ideal configuration for future green cities in Europe

1. BIPV is a beautiful, economical and multifunctional new building material and transformation method

BIPV is suitable for a variety of surfaces (roofs, Windows and exterior walls) and provides integrated solutions for achieving near-zero emission buildings: BIPV provides protective skin for buildings such as heat insulation and sound insulation; BIPV produces renewable energy power directly for buildings, contributing to more sustainable heating and power consumption; BIPV can also complement the building's intelligent functions, such as real-time heat or lighting regulation, which cannot be achieved with traditional building materials. In summary, BIPV provides a cost-effective integrated system that enables users to use decarbonized electricity and further save energy through its insulation.

For new building materials, BIPV's innovative design concept combines flexibility, versatility and aesthetics to meet the requirements of zero-carbon buildings and productive buildings. In contrast to the standard photovoltaic modules produced in new solar plants, the BIPV solution is flexible in size, shape and color, which means it can be adapted to the shape and design of the building. They can enhance energy capture on roofs, outside walls and even translucent Windows. As a result, the area available to generate clean energy is larger than that of traditional photovoltaic technologies. It will become a "must-have" for new buildings in historic districts and cities where space is increasingly scarce. Thus, with a one-time investment, BIPV technology is able to realize the building's full potential for clean energy power generation, temperature regulation and insulation.

In addition, the decarbonisation of Europe's existing buildings requires complex investments in energy efficiency and heating and cooling facilities, where BIPV can play a decisive role. BIPV technology can reduce the overall investment cost of deep renovations and achieve true commercial applications by saving materials (replacing traditional building materials with PVS) and additional revenue from on-site power generation. Although BIPV costs more than typical building materials, in most cases the added cost can be offset by the additional revenue generated by electricity generation.

2. BIPV can drive the clean energy industry in Europe and create jobs

BIPV is an untapped technology with great industrial potential. The BIPV market is a smart ecosystem of small and medium enterprises and local energy suppliers, from raw materials to products, often concentrated locally. The BIPV value chain is one way to achieve the energy transformation in Europe, where cities can benefit from the competitiveness and job creation brought about by the development of the BIPV mass market. BIPV technology is an important asset in improving living conditions in European cities, providing cleaner and cheaper electricity, reducing air pollution, increasing the energy efficiency of existing buildings and conserving energy. Because it has not yet been deployed on a large scale, the advantages of BIPV in terms of energy independence and resilience, and achieving efficient and multifunctional buildings within the limits of urban planning, have not yet been realized.

Iii. Policy recommendations to promote the application of BIPV

While there is potential to popularize BIPV in urban buildings, several obstacles remain to be overcome, such as low building renovation rates, slow progress in integrating renewable energy, and a lack of awareness of the advantages of BIPV. The municipality should actively promote BIPV and accelerate the path to a green city through the following measures:

(1) Apply BIPV to convert existing public buildings into production capacity buildings, so as to carry out better practice. The installation of on-site renewable energy power generation equipment in the traditional building industry is based on the customer ownership business model, and the building owner assumes the risks associated with operation, maintenance and decommissioning, which impedes the application of BIPV. Several new business models have emerged in the EU, which can mitigate investment risks and adapt to the development of BIPV, and have been recognized by EU regulations, such as the Renewable Energy Electricity Purchase Agreement (PPA), lease contract and Contract energy Management (EPC). In addition, city managers can improve the procurement process to support the transition to low-carbon products.

(2) Promote new private owner financing schemes, such as the energy contracting and leasing model for BIPV facilities. Governments can promote incentives that are better suited to urban needs to promote the low-energy transformation of private buildings. Such as incentives for renewable power in terms of taxes and electricity bills, and the potential of BIPV to be unlocked through an appropriate carbon price. In addition, should adopt innovative financing way to fund BIPV project, such as local tax revenue preferential policy, property tax and bonds, loans of energy efficiency, green circulating funds, soft loans, public-private partnership (third party financing), contract energy management of the private sector, public energy service company (ESCO), a feed-in tariff, citizens cooperative or the raise, etc.

(3) Develop effective policies, grid regulations and incentives to electrify systems in construction, heating and cooling, and transportation. Municipal authorities should design the right regulatory incentives to encourage the pilot project and practice cases to demonstrate the benefits of BIPV, beacon through smart city projects provide experience for the application of other cities, and according to the current situation and the city itself needs to set up the appropriate energy and climate program, and determine the corresponding fiscal policy, etc.